This is a string in the user_settings table, I assume we need to store larger values here?

Suggestion:

With this list you can specify who can send mail to the distribution list."
. " You can put a complete email address (jane@kolab.org), domain (kolab.org) or suffix (.org) that the sender email address is be compared to."
. " If the list is empty, mail from anyone is allowed.

It was a string initially, but later on changed to text. So, this is consistent, the default 'string' column length is not enough, indeed.

Thx, I'll change that.